[lld] [lld][MachO] Prevent doubled N_SO when comp_dir and name absolute (PR #71608)

[Daniel Thornburgh via llvm-commits]

mysterymath wrote:

> LGTM, and thanks for fixing this! Will you need someone to commit this for you?

Nah, I've got it. Thanks though! :)

https://github.com/llvm/llvm-project/pull/71608